1/*
2 * Copyright 2015 Red Hat Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial busions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 * Authors: Ben Skeggs <bskeggs@redhat.com>
23 */
24#define g94_i2c_aux(p) container_of((p), struct g94_i2c_aux, base)
25#include "aux.h"
26
27struct g94_i2c_aux {
28	struct nvkm_i2c_aux base;
29	int ch;
30};
31
32static void
33g94_i2c_aux_fini(struct g94_i2c_aux *aux)
34{
35	struct nvkm_device *device = aux->base.pad->i2c->subdev.device;
36	nvkm_mask(device, 0x00e4e4 + (aux->ch * 0x50), 0x00310000, 0x00000000);
37}
38
39static int
40g94_i2c_aux_init(struct g94_i2c_aux *aux)
41{
42	struct nvkm_device *device = aux->base.pad->i2c->subdev.device;
43	const u32 unksel = 1; /* nfi which to use, or if it matters.. */
44	const u32 ureq = unksel ? 0x00100000 : 0x00200000;
45	const u32 urep = unksel ? 0x01000000 : 0x02000000;
46	u32 ctrl, timeout;
47
48	/* wait up to 1ms for any previous transaction to be done... */
49	timeout = 1000;
50	do {
51		ctrl = nvkm_rd32(device, 0x00e4e4 + (aux->ch * 0x50));
52		udelay(1);
53		if (!timeout--) {
54			AUX_ERR(&aux->base, "begin idle timeout %08x", ctrl);
55			return -EBUSY;
56		}
57	} while (ctrl & 0x03010000);
58
59	/* set some magic, and wait up to 1ms for it to appear */
60	nvkm_mask(device, 0x00e4e4 + (aux->ch * 0x50), 0x00300000, ureq);
61	timeout = 1000;
62	do {
63		ctrl = nvkm_rd32(device, 0x00e4e4 + (aux->ch * 0x50));
64		udelay(1);
65		if (!timeout--) {
66			AUX_ERR(&aux->base, "magic wait %08x", ctrl);
67			g94_i2c_aux_fini(aux);
68			return -EBUSY;
69		}
70	} while ((ctrl & 0x03000000) != urep);
71
72	return 0;
73}
74
75int
76g94_i2c_aux_xfer(struct nvkm_i2c_aux *obj, bool retry,
77		 u8 type, u32 addr, u8 *data, u8 *size)
78{
79	struct g94_i2c_aux *aux = g94_i2c_aux(obj);
80	struct nvkm_i2c *i2c = aux->base.pad->i2c;
81	struct nvkm_device *device = i2c->subdev.device;
82	const u32 base = aux->ch * 0x50;
83	u32 ctrl, stat, timeout, retries = 0;
84	u32 xbuf[4] = {};
85	int ret, i;
86
87	AUX_TRACE(&aux->base, "%d: %08x %d", type, addr, *size);
88
89	ret = g94_i2c_aux_init(aux);
90	if (ret < 0)
91		goto out;
92
93	stat = nvkm_rd32(device, 0x00e4e8 + base);
94	if (!(stat & 0x10000000)) {
95		AUX_TRACE(&aux->base, "sink not detected");
96		ret = -ENXIO;
97		goto out;
98	}
99
100	nvkm_i2c_aux_autodpcd(i2c, aux->ch, false);
101
102	if (!(type & 1)) {
103		memcpy(xbuf, data, *size);
104		for (i = 0; i < 16; i += 4) {
105			AUX_TRACE(&aux->base, "wr %08x", xbuf[i / 4]);
106			nvkm_wr32(device, 0x00e4c0 + base + i, xbuf[i / 4]);
107		}
108	}
109
110	ctrl  = nvkm_rd32(device, 0x00e4e4 + base);
111	ctrl &= ~0x0001f1ff;
112	ctrl |= type << 12;
113	ctrl |= (*size ? (*size - 1) : 0x00000100);
114	nvkm_wr32(device, 0x00e4e0 + base, addr);
115
116	/* (maybe) retry transaction a number of times on failure... */
117	do {
118		/* reset, and delay a while if this is a retry */
119		nvkm_wr32(device, 0x00e4e4 + base, 0x80000000 | ctrl);
120		nvkm_wr32(device, 0x00e4e4 + base, 0x00000000 | ctrl);
121		if (retries)
122			udelay(400);
123
124		/* transaction request, wait up to 2ms for it to complete */
125		nvkm_wr32(device, 0x00e4e4 + base, 0x00010000 | ctrl);
126
127		timeout = 2000;
128		do {
129			ctrl = nvkm_rd32(device, 0x00e4e4 + base);
130			udelay(1);
131			if (!timeout--) {
132				AUX_ERR(&aux->base, "timeout %08x", ctrl);
133				ret = -EIO;
134				goto out_err;
135			}
136		} while (ctrl & 0x00010000);
137		ret = 0;
138
139		/* read status, and check if transaction completed ok */
140		stat = nvkm_mask(device, 0x00e4e8 + base, 0, 0);
141		if ((stat & 0x000f0000) == 0x00080000 ||
142		    (stat & 0x000f0000) == 0x00020000)
143			ret = 1;
144		if ((stat & 0x00000100))
145			ret = -ETIMEDOUT;
146		if ((stat & 0x00000e00))
147			ret = -EIO;
148
149		AUX_TRACE(&aux->base, "%02d %08x %08x", retries, ctrl, stat);
150	} while (ret && retry && retries++ < 32);
151
152	if (type & 1) {
153		for (i = 0; i < 16; i += 4) {
154			xbuf[i / 4] = nvkm_rd32(device, 0x00e4d0 + base + i);
155			AUX_TRACE(&aux->base, "rd %08x", xbuf[i / 4]);
156		}
157		memcpy(data, xbuf, *size);
158		*size = stat & 0x0000001f;
159	}
160out_err:
161	nvkm_i2c_aux_autodpcd(i2c, aux->ch, true);
162out:
163	g94_i2c_aux_fini(aux);
164	return ret < 0 ? ret : (stat & 0x000f0000) >> 16;
165}
166
167int
168g94_i2c_aux_new_(const struct nvkm_i2c_aux_func *func,
169		 struct nvkm_i2c_pad *pad, int index, u8 drive,
170		 struct nvkm_i2c_aux **paux)
171{
172	struct g94_i2c_aux *aux;
173
174	if (!(aux = kzalloc(sizeof(*aux), GFP_KERNEL)))
175		return -ENOMEM;
176	*paux = &aux->base;
177
178	nvkm_i2c_aux_ctor(func, pad, index, &aux->base);
179	aux->ch = drive;
180	aux->base.intr = 1 << aux->ch;
181	return 0;
182}
183
184static const struct nvkm_i2c_aux_func
185g94_i2c_aux = {
186	.xfer = g94_i2c_aux_xfer,
187};
188
189int
190g94_i2c_aux_new(struct nvkm_i2c_pad *pad, int index, u8 drive,
191		struct nvkm_i2c_aux **paux)
192{
193	return g94_i2c_aux_new_(&g94_i2c_aux, pad, index, drive, paux);
194}
195